--- a/src/hotspot/share/gc/z/zObjectAllocator.cpp Wed Nov 20 10:37:46 2019 +0100
+++ b/src/hotspot/share/gc/z/zObjectAllocator.cpp Wed Nov 20 10:37:46 2019 +0100
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -25,6 +25,7 @@
#include "gc/z/zCollectedHeap.hpp"
#include "gc/z/zGlobals.hpp"
#include "gc/z/zHeap.inline.hpp"
+#include "gc/z/zHeuristics.hpp"
#include "gc/z/zObjectAllocator.hpp"
#include "gc/z/zPage.inline.hpp"
#include "gc/z/zStat.hpp"
@@ -43,12 +44,21 @@
static const ZStatCounter ZCounterUndoObjectAllocationFailed("Memory", "Undo Object Allocation Failed", ZStatUnitOpsPerSecond);
ZObjectAllocator::ZObjectAllocator() :
+ _use_per_cpu_shared_small_pages(ZHeuristics::use_per_cpu_shared_small_pages()),
_used(0),
_undone(0),
_shared_medium_page(NULL),
_shared_small_page(NULL),
_worker_small_page(NULL) {}
+ZPage** ZObjectAllocator::shared_small_page_addr() {
+ return _use_per_cpu_shared_small_pages ? _shared_small_page.addr() : _shared_small_page.addr(0);
+}
+
+ZPage* const* ZObjectAllocator::shared_small_page_addr() const {
+ return _use_per_cpu_shared_small_pages ? _shared_small_page.addr() : _shared_small_page.addr(0);
+}
+
ZPage* ZObjectAllocator::alloc_page(uint8_t type, size_t size, ZAllocationFlags flags) {
ZPage* const page = ZHeap::heap()->alloc_page(type, size, flags);
if (page != NULL) {
@@ -72,7 +82,7 @@
size_t size,
ZAllocationFlags flags) {
uintptr_t addr = 0;
- ZPage* page = *shared_page;
+ ZPage* page = OrderAccess::load_acquire(shared_page);
if (page != NULL) {
addr = page->alloc_object_atomic(size);
@@ -142,7 +152,7 @@
// Non-worker small page allocation can never use the reserve
flags.set_no_reserve();
- return alloc_object_in_shared_page(_shared_small_page.addr(), ZPageTypeSmall, ZPageSizeSmall, size, flags);
+ return alloc_object_in_shared_page(shared_small_page_addr(), ZPageTypeSmall, ZPageSizeSmall, size, flags);
}
uintptr_t ZObjectAllocator::alloc_small_object_from_worker(size_t size, ZAllocationFlags flags) {
@@ -294,7 +304,7 @@
size_t ZObjectAllocator::remaining() const {
assert(ZThread::is_java(), "Should be a Java thread");
- ZPage* page = _shared_small_page.get();
+ const ZPage* const page = OrderAccess::load_acquire(shared_small_page_addr());
if (page != NULL) {
return page->remaining();
}